1. Technical Field
The inventive arrangements relate generally to a method and apparatus for providing advanced operating features for audio only, video only and both video and audio programs recorded on recordable and re-writable disk media, for example recordable digital video disks, hard drives and magneto optical disks, and more particularly to a method and apparatus for disaster recovery for re-writable disk media.
2. Description of the Related Art
Various devices have been developed to enable consumers to record video and/or audio programs for later presentation. Such devices include tape recorders, video cassette recorders, recordable compact disks, and most recently, recordable digital video disks (DVD). Hard drives and magneto optical disks have also been used. A DVD in which data can be recorded once only, and thereafter is essentially a DVD read only memory, is referred to by the acronym DVD-R. The acronym DVD-R also has been used generally to refer to write-once, or record-once, technology. In contrast to DVD-R, several formats exist in which data can be recorded to a DVD, erased and re-recorded. In sum, such a DVD can be overwritten or rewritten. These DVDs typically are referred to by the acronyms DVD-RAM, DVD-RW and DVD+RW. Although, as of this time no uniform industry standard has been adopted, the acronyms DVD-RAM, DVD-RW and DVD+RW have been used generally to refer to the respective rewritable technologies. Still, reference herein to re-writable DVD technology, devices and methods is generally intended to encompass all of the standards which are now being used, as well as those which may be developed in the future.
Present DVDs can have a logical file structure in which audio-video content can be stored. Specifically, as shown in FIG. 9, at the top of the file structure hierarchy of a DVD 900, one or more titles 901 can exist which can loosely correlate to program episode titles. Titles 901 can consist of control data 902 in addition to one or more Video Object Sets 903 (VOBS). The control data 902 can contain information for managing the title 901. Each VOBS 903 can include a plurality of Video Objects (VOB) 904. Each VOB 904 preferably includes a plurality of Cells 905. Each Cell 905 preferably includes a plurality of Video Object Units (VOBU) 906. Each VOBU 906 roughly correlates to a group of pictures which is the smallest addressable chunk in the DVD 900.
Notably, each VOBU 906 can contain an integer number of video frames. As such, each VOBU 906 can contain 0.4 to 1.0 seconds of presentation material. A typical VOBU 906 in a commercial motion picture can contain 0.5 second of presentation material. Notably, each VOBU 906 can include a sequence of packs 907 positioned in recording order. Preferably, each VOBU can begin with a navigation pack 908 (NV_PCK or NAV_PACK) which can be followed by audio-visual data packs 909, for example video packs (V_PCK), audio packs (A_PCK) and sub-picture packs (SP_PCK). The NV-PCK 908 can contain navigation information, which can be useful in implementing trick modes of operation. The NV_PCK 908 also can include presentation control information (PCI) and data search information (DSI).
Notably, all disk media and devices for recording and playing back program data are subject to data disasters. Data disasters are generally thought of as being characterized by the total or partial loss of data on the disk as the data is written onto the disk, read from the disk, or both. In particular, data disasters can result, for example, from the unexpected loss of power during recording or an accidental ejection of a disk. Data disasters also can be caused by the locking-up or unintentional non-responsive state of the media recorder. When a media recorder enters a non-responsive state, typically the sole recovery method is an intentional interruption of power in order to reset the media recording device.
Data disasters can cause the loss of all information in the memory of a disk media recorder. For example, if during the recording of a sporting event, the recording device loses power, all data residing in memory, including control information, will have been lost. Still, if the recording device subsequently regains power, the user may want to resume recording the event. Resuming recording, however, can prove problematic inasmuch as loss of control information can risk the overwriting of previously recorded data with newly recorded data. Hence, there exists a need for developing new methods for recovering from data disasters when recording data to re-writable disk media.